AD/MAKILA/14 - Engine Control Unit - Comparator/Selector Boards

The primary duty‑holders are the operators of helicopters equipped with Makila 1A or 1A1 turboshaft engines. The directive notes that these engines are installed in Eurocopter AS 332 C, C1, L and L1 helicopters, although the wording “but not limited to” suggests other types may also be affected. Anyone who holds an air operator’s certificate (AOC) or who operates such an aircraft under a private or aerial work operation must ensure that the ECU boards on each engine meet the requirements. Maintenance organisations that perform scheduled inspections or component overhauls on these engines are also directly affected, because they will be the entities actually carrying out the inspections and replacements prescribed by the MSBs. The manufacturer, Turboméca, is not directly addressed by the directive but is the source of the MSBs that prescribe the corrective action. The Civil Aviation Safety Authority (CASA) is the enforcement body: the directive was issued by a Delegate of CASA. Third parties such as component suppliers and distributors of CS boards need to be aware of the suspect batch to avoid supplying affected boards to operators. The compliance burden falls disproportionately on owners of aircraft operating in remote or private operations, where the cost of grounding an aircraft for the 50‑hour or 500‑hour compliance actions may be significant. The directive also creates a timing risk: the compliance date for Requirement 2 (30 November 2009) could arrive before the next scheduled 500‑hour inspection, forcing an earlier unscheduled maintenance event. Operators with fleets of helicopters will need to coordinate part supply and maintenance slots across multiple aircraft, and any shortage of replacement boards not from the suspect batch could delay compliance and ground aircraft. The directive does not mention any compensation or transitional financial assistance for the mandated replacements, so the entire cost falls on the operator.

The central duty is to replace CS boards as specified. For Requirement 1, the duty is conditional: if both boards on the same helicopter are from the suspect batch and both have fewer than 200 hours time since new, the operator must replace at least one of them within 50 hours time in service. If the condition is not met (e.g., one board has more than 200 hours), Requirement 1 does not apply, but Requirement 2 still obliges eventual replacement of both suspect batch boards. For Requirement 2, the duty is unconditional for any suspect batch board: it must be replaced during the next 500‑hour routine inspection or by 30 November 2009, whichever occurs first. The operator has a right to choose which of the two engines’ boards to replace first under Requirement 1, as long as at least one is replaced. The directive also grants a compliance alternative: if boards were already replaced before the effective date using MSB 298 73 0810 Version A (or later approved versions), that counts as compliance with Requirement 2. This reduces unnecessary duplication. Operators have a right to use later versions of the MSBs approved by EASA, which may incorporate improvements or clarifications. The directive does not create a right to an extension of the compliance time; any extension would require a separate CASA decision under the relevant regulations. There is no expressed right to deviate from the MSB instructions; strict adherence is mandated. However, the operator retains the general legal right to apply for an alternative means of compliance under the airworthiness framework (e.g., CASR Part 39), though the directive itself does not mention that avenue. The duty is strict and does not require proof that a malfunction has occurred; it is precautionary based on the identified risk. The duty also extends to record‑keeping: the replacement must be documented in the engine logbook or aircraft maintenance record to demonstrate compliance.

The directive itself does not state specific monetary penalties, because it operates under the broader enforcement framework of the Civil Aviation Act 1988 and the Civil Aviation Safety Regulations (CASR). Failure to comply with an airworthiness directive is a breach of the regulations. Under the Act, an aircraft that does not meet its airworthiness requirements cannot be operated lawfully. The penalties can be severe. For an individual, the maximum penalty for operating an aircraft not in compliance with an AD may include fines of up to tens of thousands of dollars per offence, and in some cases criminal liability for recklessly endangering the safety of the aircraft. For corporations, fines can be significantly higher. Additionally, CASA can suspend or cancel an air operator’s certificate, or issue a direction to ground the aircraft. The enforcement history for similar ADs shows that CASA takes non‑compliance seriously, especially when a known safety defect is not rectified. The background of AD/MAKILA/14 refers to “several occurrences” of unexplained backup activation and “erratic engine behaviour” such that “the potential therefore existed for a hazardous condition.” This language indicates a strong safety justification, which would likely lead to swift enforcement if an operator ignores the directive. The directive also notes that earlier AD/MAKILA/9 was already in place for the TU250 modification, so the regulator’s attention is heightened. While no specific enforcement actions are recorded in the text, operators must anticipate that any inspection by CASA or an authorised person will check compliance with current ADs. Civil liability for personal injury or property damage arising from failure to comply could also expose an operator to negligence claims, and insurers may exclude coverage if a known AD was not complied with. The absence of a penalty section in the directive does not mean the obligations are weak; they are backed by the entire suite of aviation safety legislation.

AD/MAKILA/14 is part of a multi‑layer regulatory framework. It is issued under the authority of the Civil Aviation Act 1988 and the Civil Aviation Safety Regulations (specifically, CASR Part 39, which governs airworthiness directives). The directive itself notes that EASA AD 2009‑0090 refers, which is the European equivalent. Because the Makila engine is a French‑manufactured product, the original corrective action was developed by Turboméca (now Safran) and approved by EASA. CASA’s directive adopts that corrective action for the Australian register. This means that an Australian operator who also operates in EASA‑regulated territory must comply with both directives. The text does not state whether they are identical, but the requirements are likely to be the same. The directive also interacts with the maintenance regulations under CASR Part 42 (continuing airworthiness) and Part 145 (approved maintenance organisations). A Part 145 organisation that performs the mandated replacement must be authorised for that work and must follow the MSB instructions. The directive does not override any contractual obligations between an operator and a lessor or financier; rather, it imposes a mandatory duty that must be fulfilled regardless of any lease or maintenance agreement. If the operator outsources maintenance, the duty ultimately rests with the registered operator of the aircraft. The directive also has implications for the aircraft’s certificate of airworthiness: if the AD is not complied with, the aircraft is not airworthy and the certificate may be suspended. There is no specific mention of interaction with environmental or labour laws, but the replacement may involve handling of hazardous materials (varnishes, electronic components) and occupational health and safety obligations would apply during the maintenance task.

The text of AD/MAKILA/14 does not provide an explicit amendment history beyond stating that it becomes effective on 12 May 2009 and that the earlier AD/MAKILA/9 (EASA AD 2007‑0144) mandated the original installation of the TU250 modification. The current directive therefore supersedes or supplements that earlier directive by adding a further mandatory action (replacement of suspect batch boards). There is also mention that MSB 298 73 0810 was initially issued as Version A (12 February 2008) and later revised to Version B (27 April 2009); compliance with Version A is acceptable for Requirement 2. This signals that Turboméca updated the service bulletin to reflect the new information about the varnishing defect, and the directive incorporates that update. The directive itself does not appear to have been amended later, at least not within the source text. It is common for CASA to issue a single‑shot AD that is later superseded by a new AD if further problems emerge. The absence of amendment history in the text means that for any subsequent changes, one would need to search the CASA AD database for later directives applying to the Makila engine. Because the directive dates from 2009, it is likely that subsequent ADs have been issued for different or remaining issues, but that is not part of the source. The directive also incorporates by reference the MSBs, which may themselves be revised; later versions approved by EASA are acceptable, so the directive has a built‑in mechanism for staying current without formal amendment.

The source text for AD/MAKILA/14 does not mention any litigation. This is typical for a mid‑life airworthiness directive addressing a manufacturing quality issue. To the extent that litigation has occurred, it would have arisen from incidents caused by the varnishing defect before the AD was issued. The background mentions “several occurrences of 65% N1 backup activation remain unexplained” and “a few occurrences of erratic engine behaviour” after TU250 boards were installed. If any of those occurrences led to accidents, property damage, or loss of life, there may have been lawsuits against Turboméca (product liability) or against operators or maintainers (negligence). However, the directive itself is a regulatory instrument and does not record such cases. In the Australian context, an airworthiness directive can become evidence in a civil suit: compliance or non‑compliance may be used to show whether a party exercised due diligence. It is also possible that a party subject to enforcement action by CASA for failing to comply with AD/MAKILA/14 has challenged the directive in the Administrative Appeals Tribunal or the Federal Court. No such challenges are recorded in the source. Given the specific and narrow scope of the directive, and the clear evidence of a manufacturing defect, any challenge on the merits would be difficult. Operators who delayed compliance might argue that the AD was overly broad, but the regulator’s justification based on service experience and manufacturer investigation makes that a weak argument. The directive therefore has likely been complied with without litigation, though the possibility of private disputes over cost allocation (e.g., who pays for the replacements under a lease) is real but outside the public record of the AD.

Several aspects of AD/MAKILA/14 can trap an unwary operator. First, the requirement is not merely to replace boards when a malfunction occurs; it is a mandatory advance replacement based solely on serial number and, for Requirement 1, operating time. Even if the board has performed flawlessly for 150 hours, if it is in the suspect batch and paired with another suspect batch board both under 200 hours, one must be replaced within 50 hours. The operator cannot wait for symptoms. Second, the compliance timing for Requirement 2 is phrased as “the next 500‑hour routine inspection, or before 30 November 2009, whichever occurs first.” If the next 500‑hour inspection is due in December 2009, the earlier date of 30 November 2009 applies, forcing an unscheduled maintenance event. Operators must not assume that the 500‑hour interval will predominate. Third, the exemption for boards with “more than 200 hours of trouble‑free operation” in Requirement 1 is limited to the immediate replacement step. Those boards are still covered by Requirement 2 and must be replaced eventually. An operator might falsely believe that once one board is replaced, the other is safe indefinitely. Not so: Requirement 2 demands replacement of all suspect batch boards regardless. Fourth, the directive says replacements done before the effective date using MSB 298 73 0810 Version A are acceptable for Requirement 2. But if the operator used Version A but did not replace all suspect batch boards (e.g., replaced only one board), that does not satisfy Requirement 2 fully. The earlier action must have been a complete replacement of all suspect batch boards. Fifth, the directive allows later versions of the MSBs approved by EASA. If an operator uses an unofficial version or a version not yet approved, it does not count as compliance. The operator must verify approval status. Sixth, the directive does not specify who bears the cost. Operators cannot assume the manufacturer or CASA will reimburse them. The cost of boards, labour, and any grounded‑aircraft downtime is borne by the operator. For a commercial operator, an unscheduled grounding can cause lost revenue and potential breach of service contracts. Seventh, Note 3 states “EASA AD 2009‑0090 refers.” An operator who holds a dual registration (Australian and EASA) must check whether the EASA AD has different compliance times or requirements. The Australian AD does not explicitly state that compliance with the EASA AD satisfies the Australian AD; it only says the EASA AD “refers.” Operators should seek a formal acceptance or verify equivalency. Eighth, the directive’s applicability includes “Makila 1A and 1A1 turboshaft engines, all serial numbers.” That means even engines that have never exhibited any backup control issues are covered if they have the suspect CS boards. The AD is defect‑based, not incident‑based. Finally, the requirement to comply with MSB instructions means the operator must obtain the correct MSB and follow it exactly. Mistakes in the maintenance process could lead to improper installation or testing, creating a new hazard or invalidating compliance.

Compliance with AD/MAKILA/14 involves a six‑step process. First, identify the affected engines. Locate the Makila 1A or 1A1 engines on each aircraft in the fleet. Second, determine the ECU part number configuration. If the ECU is equipped with TU250 CS boards, record the serial numbers of both boards on each engine. Check whether those serial numbers fall within the range 241 EL to 1192 EL (the suspect batch). Third, for each helicopter with both engines having suspect batch boards, check the operating time since new for each board. If either board has more than 200 hours, Requirement 1 does not apply. However, if both boards have fewer than 200 hours, then Requirement 1 is triggered: you must replace at least one of them within 50 hours time in service from 12 May 2009. That means scheduling maintenance within that tight window. As a practical matter, if the 50‑hour deadline is approaching and you have not yet done the replacement, you should ground the aircraft until the work is done. Fourth, plan for Requirement 2. Regardless of the outcome of Requirement 1, every suspect batch board must be replaced. The deadline is the next 500‑hour routine inspection or 30 November 2009, whichever comes first. Calculate for each engine the estimated date of the next 500‑hour inspection based on current usage. If that date falls after 30 November 2009, you must replace all suspect boards by 30 November 2009 (or earlier, if a 500‑hour inspection occurs sooner). If the 500‑hour inspection will occur before 30 November 2009, then do the replacement at that inspection. Fifth, obtain the correct Turboméca MSB for the replacement. For Requirement 1, use MSB 298 73 0809 Version A (or later approved version). For Requirement 2, use MSB 298 73 0810 Version B (Version A is acceptable only if already accomplished before the effective date). Ensure the MSB is approved by EASA or accepted by CASA. Order replacement boards that are not from the suspect batch from an approved stockist. Sixth, have the replacement performed by a CASR Part 145‑approved maintenance organisation with the appropriate engine and component ratings. The work must be carried out in accordance with the MSB instructions, including any testing or functional checks. Record the compliance in the engine logbook or the aircraft maintenance record, referencing AD/MAKILA/14, the MSB number and version, the serial numbers of the removed and installed boards, and the date of the replacement. Keep records as required by CASR Part 42. Finally, before the aircraft returns to service, verify that all applicable requirements are satisfied, including any airworthiness release. If you have previously replaced suspect batch boards before the effective date of this directive, using MSB 298 73 0810 Version A, you may skip Requirement 2, but you must still comply with Requirement 1 if it applied. Double‑check that the earlier replacement covered all suspect batch boards on that helicopter. Periodic audits of your AD compliance status will help avoid inadvertent non‑compliance, especially as new ADs are issued for the same engine family.